It’s out with the old yardstick and in with the new as professional organizations that keep tabs on the height and weight of Canadian children turn to “superior” growth charts based on World Health Organization standards.
The monitoring charts for newborns to age five show how children should grow, rather than how they do grow, while the new charts for ages five to 19 are a better tool for identifying young people at risk for obesity.
A collaborative statement said the four leading national health groups have decided to move away from using charts developed by the U.S. Centres for Disease Control and Prevention, which included the full range of American kids — including those routinely exposed to second-hand smoke and those who weren’t immunized or breastfed.
“These new charts are actually much superior to what we’ve had in the past,” said Tanis Fenton, a spokeswoman for Dietitians of Canada, one of the groups involved.
The children who were studied for the WHO standards up to age five lived in six different countries — Brazil, Ghana, India, Norway, Oman and the United States, and thus reflect the ethnic diversity in Canada.
They were healthy, had routine medical care and appropriate immunizations, lived in non-smoking environments, and were exclusively breastfed for four to six months.
“So these children formed a group that we feel that their growth is a standard, a type of growth that we feel children should grow at,” said Fenton, who’s a registered dietitian and epidemiologist in Calgary.
The Canadian Paediatric Society, the College of Family Physicians of Canada and Community Health Nurses of Canada were also part of the project to adapt the WHO charts for use in this country. Dr. Leslie Rourke, a representative for the CFPC, said the charts come with imperial and metric measures, and there are English and French versions.
It’s important to track the growth of children to pick up on possible health and nutrition problems, she said.
The WHO measured children with optimal nutrition and health conditions in the six countries and found only a three per cent difference in the way children from the different countries grew.
Meanwhile, the CDC charts reflected much higher incidences of overweight and obese children, she said.
Fenton noted that WHO charts to track body mass index are also part of the new package, and can be used after age two.
“They are actually very helpful, particularly as children get close to puberty, because the timing of puberty varies from child to child,” she said. “And when you’re evaluating the BMI then you’re not just comparing their size to their age. So it can be quite helpful to use the BMI. And it’ll be interesting to see how we all get used to using them.”
In terms of the difference between the CDC and WHO charts, both Rourke and Fenton explained that growth patterns are actually a bit higher on the WHO charts in the first six months, and then a little bit lower after six months.
“This actually reflects what we know about the growth of breastfed babies,” Fenton said.
“Breastfed babies actually grow faster than formula-fed babies — just a little bit faster — in the first six months of age, and then they tend to gain weight a little bit slower after that.”
But the charts are suitable for bottle-fed children as well, Rourke added.
Dr. Valerie Marchand, chair of the Canadian Paediatric Society’s nutrition and gastroenterology committee, said it’s recommended that children be weighed and measured by their health-care provider within one to two weeks of birth, at two, four, six, nine, 12, 18 and 24 months, and then once per year for children over two and adolescents.
Fenton said the new tools are being introduced amid an awareness by health-care providers that our population is getting heavier.
“It’s appropriate to have a good growth standard to compare children to so that we’re confident about whether or not the child is larger than we think is desirable,” she said.
“And if they are identified as being larger than we think is desirable, then the Canadian Medical Association has recommendations to consider multi-factoral approaches to working with families to see if we can turn things around a little bit.”